OPTICAL NODE DEVICE AND OPTICAL COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an optical node device capable of securely detecting fault occurrence at low costs.SOLUTION: An optical node device connected to a center device through an optical transmission line includes: downward light reception means (PD 201) for receiving downward light transmitted from the center device through the optical transmission line; upward light transmission means (LD unit 211) for transmitting upward light to the center device through the optical transmission line; detection means (CPU 208) for detecting fault occurrence on the basis of the downward light received by the downward light reception means; and notification means (CPU 208) for notifying the center device of the fault occurrence by controlling the upward light transmission means using a modulation scheme different from the upward light, when the fault occurrence is detected by the detection means.